1. Field of Invention
This invention relates to a parts feeding and receiving mechanism of the type in which a parts feeding member and a parts receiving member are provided each with a magnet.
2. Description of Prior Art
As far as my research covers, there has been found no known example in which a parts feeding member and a parts receiving member are provided each with a magnet. However, among what I have proposed, there is one shown in FIG. 6. The part handled therein is an iron bolt 1 having a flange-like head 2 and a stem 3. A feeding member 4 is adapted to be moved vertically and horizontally, and a parts receiving member 5 is adapted to be moved vertically. The front end of the feeding member 4 is formed with a notch 6, in which a magnet 7 for holding a part is installed. The magnet 7 is embedded in the feeding member 4 and has a protective plate 8 mounted thereon. The head 2 is attracted by the magnet 7 with its end surface contacting the protective plate 8. The feeding member 4 is connected to driving means (not shown) so that it is movable horizontally and vertically as indicated by arrows 9, 10, 11 and 12.
On the other hand, the receiving member 5 has a receiving hole 13 for the stem 3 and has a magnet 14 fixed in the innermost region of said receiving hole. The receiving member 5 receives the bolt 1 and then moves downward to feed the bolt to an intended place. Therefore, the receiving member 5 also is capable of reciprocating as indicated by arrows 11 and 12.
The operation of the feeding and receiving mechanism described above will now be described. The feeding member 4 holding the bolt 1 by the magnet 7 is moved from the left as indicated by the arrow 9 and is stopped when the stem 3 is coaxial with the receiving hole 13. Then the feeding member 4 is moved upward as indicated by the arrow 11 to insert the stem 3 into the receiving hole 13, where it is attracted by the magnet 14. Thereafter, when the feeding member 4 is retracted as indicated by the arrow 12, the bolt 1 remains in the receiving hole 13 under the attractive force of the magnet 14. After the feeding member 4 is retracted in the direction of arrow 10, the receiving member 5 starts to descend.
With the mechanism thus arranged, if the polarity of the magnet associated with the feeding member and the polarity of the magnet associated with the receiving member are not properly selected, the proper feeding and receiving of parts is impossible. To describe this in more detail, if the N-pole of the magnet 7 is directed upward and its S-pole downward, then the magnetic lines 15 pass through the bolt 1 longitudinally thereof, so that the front end of the stem 3 has an N-pole. If the polarity of the magnet 14 is such that its lower side is N and upper side is S, then the front end of the stem 3 and the magnet 14 repulse each other. This means that when the feeding member 4 descends in the direction of arrow 12, the bolt returns as it adheres to the protective plate 8 rather than remaining in the receiving hole 13; thus, the feeding and receiving operation becomes impossible.
Such problems could be solved by selecting the polarity of the magnet 14 such that it corresponds to the polarity of the magnet 7 so that it is in the attracting relation rather than the repulsing relation. However, when such magnets are so installed, mistakes can be made, resulting in the repulsing relation.